Origin and Habitat: Large area of Mexico (Chihuahua, Durango and Coahuila to Nuevo León)Habitat: It is a fairly widespread species locally very abundant with plants growing in clusters comprising hundreds of plants. Grows on alluvial soils in plains.

Description:Coryphantha delaetiana is a strongly spined globular cactus either solitary or in clusters (depending on the clone). This species has a wide range and shows a great variabilityStem: Nearly globular to short cylindrical, or sometimes club-shaped, light green, strongly spiny at the top, 6-8 cm in diameter and 6 to 15 cm high.Tubercles: Rather short, rhomboid, to 10 mm long closely set.Central spines: 1 to 4, reddish to almost black, the lowest central stronger than others but sometimes absent, 2 to 2,9 cm long, straight, extended forward or slightly curved downward, the 3 upper ones often wanting directing upward and those near top of plant converging and touching but not fused.Radial spines: Greyish or whitish, 7 to 15(-20), spreading, slender, 10 to 15(-20) mm long.Blooming habit: Flowers large pale yellow, 4 cm long. Outer perianth-segments greenish or slightly tinged with red, the inner light yellow. Filaments green-yellow. Stigma-lobes about 7.

Subspecies, varieties, forms and cultivars of plants belonging to the Coryphantha delaetiana group

Cultivation and Propagation: It is a summer-growing species of easy cultivation. It is sensitive to overwatering (rot prone) and slow-growing.Soil: Grow it in an open sandy-gritty cactus compost.Pots: It needs a relatively shallow pot to accommodate its fibrous roots and provide a very good drainage. They may stay in the same pot for many years.Watering: Water in moderation, it prefer a completely dry place during winter. Mature individuals easily rot and die especially after planting so be extremely cautious with watering. Keep dry in winter or when night temperatures remain below 10° C. Water it less than average if in bigger pots.Special need: Provide very good ventilation. Nearly all problems occur as a result of overwatering and poor ventilation, especially when weather conditions are dull and cool or very humid. Fertilization: Feed them once during the growing season with a fertilizer specifically formulated for cactus and succulents (high potash fertilizer with a dilute low nitrogen), including all micro nutrients and trace elements diluted to ½ the strength recommended on the label. They thrive in poor soils and need a limited supplies of fertilizer to avoid the plants developing excess vegetation, which is easily attacked by fungal diseases.Exposure: It will do its best with lots of sun and become stressed with inadequate light which could result in poor growth and unnatural shape. Hardiness: It likes warmth (recommended minimum winter temperature 5° C) however plants kept perfectly dry can can survive low temperatures, approx. -5°, but for safe cultivation it is best to avoid freezing temperatures. Use: It can be cultivated outdoors in raised beds, terraces if sheltered from winter rain. Pests & diseases: These cacti may be attractive to a variety of insects, but plants in good condition should be nearly pest-free, particularly if they are grown in a mineral potting-mix, with good exposure and ventilation. Nonetheless, there are several pests to watch for: - Red spiders: Red spiders may be effectively rubbed up by misting the plants from above. - Mealy bugs: Mealy bugs occasionally develop aerial into the new leaves and flowers with disfiguring results, but the worst types develop underground on the roots and are invisible except by their effects. - Scales, thrips and aphids: These insects are rarely a problem. - Rot: Rot is only a minor problem if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.Propagation: Seeds. The seeds can be sown in pots of fine, well-drained sandy soil, any time during the spring when temperatures are warm. Cover the seeds with a fine layer of grit and water from below with a fungicide to prevent damping off. For the 1-2 weeks cover the pots with a sheet of glass/clear perspex to keep the humidity levels high. Remove the glass and replace it with light shade-cloth and mist once or twice a day for the next two weeks after which most seeds should have germinated. From then on mistings can be reduced to every second and then every third day as the little plants grow.